I've used this one in literacy hour for writing instructions, but it can be used across the board to get children to think carefully about logical sequence.

I have used it with reception children, but I think it would work throughout primary years.

• Ask the class for help with making a sandwich. (Any kind of sandwich, bearing in mind that too complicated a filling will result in loads of mess)!
• Have all the ingredients ready and ask the class what to do.
• Do EXACTLY what they tell you - ie "Put the butter on the bread." - Put the unopened butter on the unopened bread.
• Obviously, the children will realise that they need to give clearer instructions.
• Keep going until finished.

Word of warning --- the lesson can become raucous and messy - but it is great fun. This sort of lesson really appeals to early years children's sense of humour.